- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Bit-interleaved polar coded modulation scheme for high-order QAM encoded DDO-OFDM systems
摘要： In the paper, a simple generation scheme of the twin-SSB-OFDM signal based on one OFDM transmitter is proposed in the direct-detection optical orthogonal frequency-division multiplexing (DDO-OFDM) system. Compared with traditional generation scheme that requires two OFDM transmitters, it has lower implementation complexity and lower cost. In addition, to enhance the spectral efficiency (SE) for DDO-OFDM system, an efficient bit-interleaved polar coded modulation (BIPCM) scheme adopting 256 quadrature-amplitude modulation (256-QAM) is proposed. Moreover, a quadratic polynomial permutation (QPP) interleaver is adopted for polar coded modulation (PCM) to further improve the overall system performance. The simulation results exhibit that the proposed scheme can achieve more than 4 dB and 5 dB Q-factor improvement compared to the conventional schemes with PCM and without BIPCM, respectively. At the same time, aided by the efficient 256-QAM BIPCM scheme, the receiver sensitivity is improved and the laser linewidth requirement is less strict compared to the conventional schemes.
关键词： Bit-interleaved polar coded modulation (BIPCM),Direct-detection optical orthogonal frequency-division multiplexing (DDO-OFDM),Single-side-band (SSB) modulation
更新于2025-09-19 17:15:36
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Research on Power Equalization of Three-phase Cascaded H-Bridge Photovoltaic Inverter Based on the Combination of Hybrid Modulation Strategy and Zero-Sequence Injection Methods
摘要： We demonstrate for the ?rst time an intensity-modulated direct-detection link using four states of polarization. The four data-independent tributaries are each assigned distinct states of polarization to enable the receiver to separate the signals. Polarization rotation due to propagation over optical ?ber is tracked and compensated with simple digital signal processing in Stokes space. Transmission below the forward error correction limit is shown for maximum net bitrates of 100 Gb/s (4 × 27 GBd) and 120 Gb/s (4 × 32 GBd) over 2-km standard single-mode ?ber at a center wavelength of 1550 nm.
关键词： direct detection (DD),intensity modulation (IM),digital signal processing,Stokes space,100G,polarization
更新于2025-09-19 17:13:59
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - Wideband Photonic Image-Reject RF Receiver Based on Phase Modulation and I/Q Balanced Detection
摘要： We demonstrate for the ?rst time an intensity-modulated direct-detection link using four states of polarization. The four data-independent tributaries are each assigned distinct states of polarization to enable the receiver to separate the signals. Polarization rotation due to propagation over optical ?ber is tracked and compensated with simple digital signal processing in Stokes space. Transmission below the forward error correction limit is shown for maximum net bitrates of 100 Gb/s (4 × 27 GBd) and 120 Gb/s (4 × 32 GBd) over 2-km standard single-mode ?ber at a center wavelength of 1550 nm.
关键词： direct detection (DD),intensity modulation (IM),digital signal processing,Stokes space,100G,polarization
更新于2025-09-19 17:13:59
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - SDN-Enabled Adaptive Modulation and Coding in Hybrid C-RANs
摘要： In this invited paper, we describe our recently proposed software-defined networking (SDN)-enabled, adaptive resource allocation framework, including hybrid signalling schemes, for mobile fronthaul (MFH) networks that employ both coherent detection (CD) and direct detection (DD) technologies. To optimize application performance and network efficiency, we propose phase-coded three-level pulse amplitude modulation (PAM-3) for multicast traffic delivery to CD and DD nodes. We implement several connectivity scenarios based on both typical and improved PAM-3 in an SDN fronthaul testbed and examine the pre-forward error correction (FEC) bit error rate (BER) performance for 25 Gbaud signals. Using low-density parity-check (LDPC) codes to achieve the desired post-FEC BER levels, we study the performance gains due to code rate adaptation in dynamic wavelength-routing MFH networks.
关键词： coherent detection (CD),centralized radio access network (C-RAN),mobile fronthaul (MFH),software-defined networking (SDN),direct detection (DD),low-density parity-check (LDPC) coding
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A Poldemux Scheme Using Extended Kalman Filter in Probabilistic Shaping Stokes Vector Direct Detection System
摘要： We propose a Kalman filter based PolDemux scheme to cope with probabilistically shaped 16QAM signals in Stokes vector direct detection system. It can track the SOP variation up to 2Mrad/s at a relative lower OSNR.
关键词： Stokes vector direct detection,Extended Kalman filter,Probabilistic shaping,Rotation of state of polarization
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Novel Four-Level Manchester Coding Technique for Optical Access Networks
摘要： Four-level Manchester coding (4-MC) technique investigated for high-speed optical access networks. Results show that 4-MC has 3.5dB better receiver sensitivity compared to 4-PAM, which makes 4-MC an alternative to 4-PAM together with self-clocking feature advantage.
关键词： Multilevel Manchester coding,direct detection,Manchester signal,access network
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Long Distance IM/DD Transmission with OFDM-QAM based Quantum Noise Stream Cipher
摘要： We propose a QAM-based quantum noise stream cipher (QNSC) scheme for IM/DD transmission employing orthogonal frequency division multiplexing (OFDM) modulation. 2.5Gbit/s IMDD-OFDM signal is demonstrated over 1000 km distance. The experimental results show that Q penalty using IMDD-OFDM based QNSC is only 1.6 dB compared to QPSK without encryption in the cases of back-to-back condition and 1000km transmission.
关键词： orthogonal frequency division multiplexing (OFDM),quantum noise stream cipher (QNSC),intensity modulation/direct detection (IM/DD)
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Probabilistic Shaping for Direct Detection Transmission With Kramers-Kronig Receiver
摘要： We introduce probabilistic shaping into direct detection system with Kramers-Kronig receiver to further improve the performance. Simulation results show that there are 0.53/0.86/1.12dB OSNR improvements by transmitting PS-16/64/256QAM signal compared with the uniform 16/64/256QAM signal.
关键词： Kramers-Kronig,direct detection,probabilistic shaping
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Industry Trends for 400 Gb/s and Beyond Applications
摘要： After the implementation of 100-Gb/s pluggable optics, the optical communications is marching towards 400-Gb/s era. We will review our recent demonstration and study for 400 Gb/s and beyond client and line side optical interconnect.
关键词： coherent communication,optical communications,400G Ethernet,direct detection,packet optics
更新于2025-09-16 10:30:52
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Performance Enhancement of Probabilistically Shaped OFDM Enabled by Precoding Technique in an IM-DD System
摘要： Probabilistically shaped orthogonal frequency-division multiplexing (PS-OFDM) signal is proposed and experimentally demonstrated in a low-cost intensity-modulation and direct-detection (IM-DD) system for optical access networks. The concatenation of constant composition distribution matcher (CCDM) and low-density parity-check (LDPC) code sequentially implements probabilistic amplitude shaping (PAS) and channel coding. Thanks to the precoding scheme, all data subcarriers can be treated equally by one optimized probabilistic distribution. Experimental results demonstrate that constant amplitude zero autocorrelation sequence (CAZAC) precoding can offer optimal performance compared to orthogonal circulant transform (OCT) precoding and discrete Fourier transform spread (DFT-spread) in terms of increasing generalized mutual information (GMI) and reducing PAPR. Moreover, probabilistically-shaped 64-QAM OFDM signal can provide shaping gains of 1.04/0.94/0.64 dB at 4.0/3.6/3.0 bits/QAM symbol compared to traditional 64-QAM OFDM signal. Meanwhile, compared to traditional 16-QAM OFDM, it can offer shaping gains of 1.64/0.64 dB at 3.6/3.0 bits/QAM symbol. In addition, net data rate ranging from 32.66 to 43.55-Gb/s over 20-km single mode fiber (SMF) can be achieved by only adjusting the probabilistic distribution.
关键词： precoding technique,optical access networks,Probabilistically-shaped orthogonal frequency-division multiplexing (PS-OFDM),intensity-modulation and direct-detection (IM-DD)
更新于2025-09-16 10:30:52